[Bug target/55212] [SH] Switch from IRA to LRA

[kkojima at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55212

--- Comment #39 from Kazumoto Kojima <kkojima at gcc dot gnu.org> ---
(In reply to Hans-Peter Nilsson from comment #38)
> Hm, you're right, but to me that indicates the patch covering-up a bug
> elsewhere than in the sh port.

Would it be better to file an independent PR for this?
It looks a latent problem of untyped_call implementations on some
targets, though I guess that it's hard to hit because untyped_call
is fairly exotic and the RA issue before that call can be happened
only on arches with non-orthogonal instruction set like SH which
heavily depends on R0.